Request you to suggest us a part to measure 115 Volts AC, 3 Phase at 400 Hz.
Please confirm us it will work at 400 Hz.
For measureing a 3 phase system at 400Hz I would recommend using a part such as the ADE7858A or ADE7868A if you want to use CT's to measure the current. If you rather use shunts for the current measurement then I would recommend the ADE7978 with the ADE7932 which has integrated isolation.
For the ADE7858A, the data sheet is based on the fundamental being between 45Hz and 65Hz. Although, there is a bandwidth specification for energy and RMS, which is 2kHz. This means that with a 400Hz fundamental, you will only measure about 5 harmonics within that bandwidth. If the metering IC has any fundamental or THD measurements, such as the ADE7878A or ADE7978, these measurements will not be accurate because the system will be looking for a 50 or 60Hz fundamental to base these measurements off of.
Many specifications from the table in the data sheet refer to a specific fundamental frequency between 45Hz and 65Hz but you should still expect similar performance at 400Hz besides what I mention above.
Thanks for your inputs.
Please help to know what kind of tweaking in terms of hardware and firmware need to be done to work on 400Hz.
No real tweaking of the hardware or firmware needs to be done for the metering IC. There are just some measurements that will have to be ignored. From the parts I listed above, do you already have one in mind that you would want to use?
Overall the part will be used just like it would with a 50 or 60Hz line except the bandwidth will limit the number of harmonics and any register that give fundamental measurements will not be available.
I am presently using the ADE7878A for 3-phase with CTs at the output of VFD (40 - 60 Hz) ahead of a motor. I have extra filtering to deal with PWM and a network to reconstruct the movement of "neutral" at the center of the "Y". This is working well. Now I have an application for 3-phase 400Hz straight off MG-sets. This is sinusoidal, but the 400Hz is a problem. I am not much concerned with the restricted 2kHz bandwidth of the DSP. Rather the 80Hz LPF1 in front of all the ZCROS detectors kill all measurements of frequency, phase, sequence, and power factor. Is there an undocumented register that can be used to by-pass the 80 Hz filter or translate its frequency upward?
Unfortunately there is no internal register to disable LPF1 in order to measure zero crossings at higher frequencies. That means, like you said, frequency and phase sequence would not function properly. Although for power factor, you could use the active and apparent energy register in order to calculate it. The fundamental power measurements would also not be accurate since it is expecting a fundamental between 45 and 65Hz.
If you need zero crossing detection then the waveforms at 8kHz would have to be used with a separate zx detection circuit.
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